This invention is directed to a mouthrinse preparation for the purposes of oral therapy and the prevention of dental disease. More particularly, the invention is directed to a chemically stable mouthrinse composition which includes hydrogen peroxide and a method for preparation of such a mouthrinse.
Hydrogen peroxide and peroxide-containing preparations are known to be effective therapeutic and prophylactic treatments for caries, periodontal hemorraging, plaque, gingivitis, periodontitis, orthodontic appliance damage and other oral conditions. Frazier et al., U.S. Pat. No. 4,980,152, disclose an oral preparation containing between 0.5% and 10% hydrogen peroxide.
Mouthrinses are known to contain numerous adjuvants in addition to hydrogen peroxide. Schiraldi et al., U.S. Pat. No. 4,992,259, disclose the use of zinc compounds including zinc chloride as astringent-desensitizing agents.
Additionally, flavorings and colorings have been added to mouthrinses to improve their acceptability to the user. Surfactants have been added to enhance the bacterial activity of the mouthrinse. Anticoagulants have also been included to help the healing of hemorragic tissue.
Oral preparations containing such other ingredients in conjunction with hydrogen peroxide, however, have generally been unstable in storage, as the hydrogen peroxide reacts with one or more of the other ingredients in the preparation and components of the mouthrinse tend to precipitate. As a result, the capacity of the hydrogen peroxide to release oxygen and of the other ingredients to perform their respective functions is lost or greatly diminished even after relatively short storage periods as, for example, on a drug store display shelf. Additionally, the instability of mouthrinses containing hydrogen peroxide has been known to render them unsatisfactory with respect to shelf-life requirements of the United States Food and Drug Administration.
Oral preparations also often contain relatively high concentrations of various alcohols for their effects of sterilizing, transporting and stabilizing. Asano et al., U.S. Pat. No. 4,568,540, disclose oral preparations having at least 35% sorbitol. Commercially available mouthrinses often contain between about 15% and 30% alcohol.
Recently there has been increasing concern about the high alcohol content of commercially available mouthrinses. Scientific studies have linked the regular use of such mouthrinses to significant increases in the incidence of oral cancer. Additionally, there is a risk that alcoholic persons may intentionally ingest high alcohol mouthrinses, that children may incur serious injuries due to poisoning from high alcohol mouthrinses, and that adolescents may abuse such mouthrinses where liquor laws otherwise render alcohol unobtainable.